Since 4/11/09 my two Digihome boxes will not pick up Cannel 62 Winter Hill so I have lost BBC programmes.
Tesco nor Vestel who make these boxes for Tesco will help.
The software is version 5.3 I believ that there is a version 5.7 which will correct the fault but it seems the manufacturer is not planning to put out this software update over the air or any other way.
If the boxes are under a couple of years old is is unlikely that they need new firmware. I'd look for aerial problems. (The frequency of the muxes may have been changed.)
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix dtt receivers.